Single strength juice deacidification incorporating juice dome

ABSTRACT

A process for deacidifying single strength juice, including not from concentrate (NFC) juice, uses an ion-exchange column. The process includes flowing water into the resin column and draining a fraction of the water from the column to create a head space in the column above the resin beads. Single strength juice is then introduced into the head space and into the resin column. Water is drained from the column until an SOI criterium is met. Single strength juice continues to be introduced into the resin column and treated liquid is directed to the production of deacidified single strength juice, typically until such time as the acidity of the treated liquid exceeds a pre-determined value. Treated single strength juice is removed from the resin column to create a head space in the column. Water then is introduced into the head space and liquid passes through the exit port.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a process and system forprocessing fruit juice and to a juice deacidification process and systemutilizing ion exchange resin columns that minimizes the amount of juicelost during the “sweeten-on/sweeten-off” ion exchange steps.

[0002] Juice products are highly popular with consumers due to boththeir taste and their nutritional value. However, some fruit juices,such as those from citrus fruits, can have a level of acidity that makesthem disagreeable to persons with sensitive stomachs.

[0003] Numerous individuals have been known to experience negativeeffects upon ingesting different foods. A true food allergy occurs whenthe immune system of the individual overreacts to certain proteins infood. It is believed that hundreds of food ingredients can provoke anallergic reaction. Typical foods in this regard are nuts, peanuts, milk,eggs, fish, shellfish, soybeans and wheat. Foods such as these can leadto symptoms including nausea, hives, skin rash, nasal congestion,wheezing, and the like. However, most unpleasant reactions to food arecaused not by allergies but by intolerances, which tend to be lesssevere than true food allergies. Typical in this regard are lactoseintolerance, sulfite intolerance and intolerance to monosodiumglutamate, red wine, chocolate and food coloring agents. Anotherintolerance of some frequency is manifested by gastral distress and/ordigestive difficulties which certain individuals experience shortlyafter ingesting orange juice products.

[0004] In some circles, it is generally assumed that the relatively highacidity of orange juice products is a primary contributor to thesenegative or unpleasant experiences with orange juice products for asmall percentage of the population. For example, Kligerman et al U.S.Pat. No. 5,665,415 and No. 5,869,119, incorporated hereinto byreference, suggest that acidic foods or beverages such as coffee andother beverages can be combined with calcium glycerophosphate so as toraise the pH of the food or beverage by at least 0.5 pH units, such asto a pH of greater than 5.4, which typically is pH higher than desirablefor superior tasting orange juice. This pH adjustment is said to reducethe tendency of the food or beverage to cause heartburn and otheresophageal and/or gastrointestinal distress. This approach generallyfollows the conventional wisdom that ingesting antacids treats heartburnby helping to neutralize stomach acid. This approach suggests, ingeneral, raising the pH of the food or beverage to well above 5.

[0005] Processes for deacidifying citrus juice have been known since the1960s, and commercially-viable deacidification processes using anionicion exchange for acid reduction of citrus fruit juices were known by1980. However, such processing was used for deacidifying juice made fromconcentrate, which has a standard of identity (SOI) that permits a greatrange of flexibility in the processing steps with respect to thedilution and blending of the juice product.

[0006] Since that time, “not from concentrate” or NFC juices have becomevery popular with consumers because of their “fresh-squeezed” taste.These NFC juices must meet their own SOI criteria. Among these criteriais the avoidance of a final juice product which has water addedcharacteristics. Other criteria typically include brix minimums andbrix-to-acid ratio minimums.

[0007] For example the US Food and Drug Administration sets a standardfor juices such as orange juice, including brix minimums. In this regard21 CFR Section 146.140, incorporated by reference hereinto, states thatfinished pasteurized orange juice is to contain not less than 10.5percent by weight of orange juice soluble solids, exclusive of thesolids of any added sweetening ingredients. This FDA regulation furtherstates that the ratio of brix to grams of citric acid per 100 ml ofjuice is not less than 10 to 1. The juice industry recognizes thesecriteria for pasteurized orange juice or single strength orange juice asapplying to-NFC orange juice. It will be understood that these SOIcriteria are used herein with respect to NFC orange juice or pasteurizedsingle strength orange juice. This same concept of SOI criteria appliesas well to other pasteurized single strength juices.

[0008] While it is anticipated that there would be a significant marketfor a low acid NFC orange juice, deacidification processes utilizingion-exchange resin columns can easily result in the processed juicebeing diluted. This is particularly true if the ion-exchange column isdesigned to operate with a water/juice interface or a “water dome” inthe head space of the column above the resin bed. Such water dilution ofthe processed juice is unacceptable for NFC juices because the standardof identity (“SOI”) of the juice is compromised.

[0009] Accordingly, it is an object of the present invention to providea process and system for deacidifying NFC juices that do not compromisethe standard of identity required for such juice products.

[0010] More particularly, it is an object of the present invention toprovide a process and system for deacidifying NFC juices that do notdilute the NFC juice so that NFC SOI can be maintained.

[0011] It is a still further object to deacidify NFC juices whileminimizing the amount of juice that is wasted or becomes otherwiseunuseable due to the deacidification process.

[0012] A further object of the invention is to provide an improvedsingle strength juice which meets SOI criteria throughout all phases ofsingle strength juice product collection.

SUMMARY OF THE INVENTION

[0013] These objects, as well as others that will become apparent uponreference to the following detailed description and accompanyingdrawings, are accomplished by a process for deacidifying single strengthjuice, preferably not from concentrate (NFC) juice that uses anion-exchange column having a lower volume portion that is filled withacid-absorbing resin beads and an upper volume portion within which theresin beads are not present. The lower volume portion has an exit port,while at least one inlet port opens into the upper volume portion.

[0014] The process includes filling the resin column with water and thendraining a fraction of the water from the column through the exit portto create a head space in the column above the resin beads. Untreatedjuice is then introduced into the resin column. In a preferredarrangement, such initial flow is through an inlet port so as tominimize resin bed disturbance. With this arrangement, after the headspace has an adequate volume of juice, untreated juice can be introducedinto the resin column. In the illustrated embodiment, this is through aninlet port which is at an upper location of the upper volume portion.Water is drained through the exit port until the outflowing treatedliquid meets SOI criteria for the single strength juice. Untreated juicecontinues to be introduced, and treated juice is collected asdeacidified single strength juice until a pre-determined value isattained, such as when a target processing volume is obtained or untilthe resin is exhausted.

[0015] Treated juice is removed from the resin column to then create ahead space in the column. In one approach, this leaves the resin beadswetted or even submerged. Alternatively, all free juice may be displacedout of the resin bed before the next phase introduces water into theresin bed. Water is then introduced into the head space in the column,and liquid passes through the exit port until the outflowing liquid doesnot meet SOI criteria for the single strength juice, at which time thisliquid is no longer directed to production.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a schematic diagram illustrating a process for producingsingle strength low acid juice products incorporating ion-exchange resincolumns in accordance with the present invention.

[0017]FIG. 2 is an enlarged schematic view of a pair of ion-exchangeresin columns for performing the process of the present invention.

[0018]FIG. 3 illustrates the deacidification process of the presentinvention with a single ion-exchange resin column (it being understoodthat the other resin column of the pair that is not shown is beingregenerated simultaneously with the deacidification being carried out inthe first resin column).

[0019] FIGS. 4A-4C are plots of pH of blended juice versus ratio ofuntreated juice to treated juice in the blended juice for various BedVolumes of juice subjected to the deacidification process of the presentinvention, the untreated juice of this illustration having a pH of 3.94and a titratable acidity of 0.61% for FIG. 4A, a 3.82 pH and 0.65%titratable acidity for FIG. 4B, and a 3.65 pH and 0.75% titratableacidity for FIG. 4C.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0020] The method of the present invention is directed to thedeacidification of single strength fruit or vegetable juice, especiallyNFC citrus juice, and is part of the process of producing a low-acidsingle strength juice product from standard single strength juice.

[0021] Deacidification of citrus juice may take place in any number ofknown devices. For example, the form of ion exchange resin equipmentused in deacidification of citrus juice may be a flow-through columnand/or a continuous system or semi-continuous system. Anotherpossibility is the use of resins in a bed formation, such as in anoverall batch approach. Ion exchange technology may be utilized todeacidify juice in any number of possible devices, provided that theresins are allowed to contact the juice during the process.

[0022] The resins used in ion exchange technology may likewise be of awide variety. Resins of any level of binding affinity may be used,depending on the acidity of the juice. In one preferred embodiment, theresin used is a weakly-basic, anionic exchange resin, often apolystyrene copolymer which contains a tertiary amine group as afunctional group. This weakly-basic resin is preferred because of itsability to pull organic acids such as citric acid from the juice,thereby producing a deacidified juice stream.

[0023] Examples of other commercial resin systems include thoseincorporating ion exchange resins such as anionic polystyrene copolymerswhich release chloride groups and basic anionic polystyrene resinshaving quaternary ammonium active groups. Specifically, resins such asAmberlite IRA-67, Amberlite IRA-95, Dowex 67, Dowex 77 and Diaion WA 30may be used.

[0024] Deacidification of juice takes place as a juice stream is passedthrough or otherwise contacts the resin bed. The juice used may be anyfruit or vegetable single strength juice which has not beenconcentrated, preferably an NFC citrus juice, including orange andgrapefruit, the most preferred juice being orange juice. To deacidifythe citrus juice using ion exchange technology, a juice stream comes incontact with the ion exchange resins. The preferred method uses a juicestream that is passed through the resin structure, such as the resin bedor column. As the juice contacts the resins, ion exchange takes place inaccordance with known principles.

[0025] In ion exchange deacidification, when the juice stream comes incontact with the resin, the ions of the juice are exchanged with thoseof the resin. In the preferred embodiment, acidic juice comes in contactwith, and is attracted to, the weakly-basic polystyrene resin. Whencitrus juice is treated, the ion exchange resin adsorbs the citrus ionsof the citrus juice. Adsorption is the accumulation of ions on a resinpore surface, resulting in a relatively high concentration of the ionsat the resin's surface. After citrate ions of the juice stream areadsorbed by the resin, the stream is substantially less acidic.

[0026] The general process for producing a low-acid single strengthjuice product such as low-acid NFC orange juice typically includes thefollowing steps: (a) heat treatment, if needed, to inactivate the pectinesterase enzyme present in the single strength juice; (b) centrifugationfor solid/liquid separation to produce a solids-reduced juice (i.e.,juice with generally less than 3 volume percent, typically less than 2volume percent, and, preferably, not more than 1 volume percent, ofsuspended solids); (c) deacidification of the solids-reduced juice, withuntreated juice optionally being added to the deacidified juiceimmediately after the deacidifying process to adjust the pH to a level(i.e., below about 4.5) that is unfavorable to microbial activity; (d)blending the deacidified solids-reduced juice with the solids that wereseparated in step (b) and additional untreated juice to the extentnecessary to obtain the desired final acidity level; (e) addingadditional ingredients such as oils, minerals and vitamins, as desired;(f) mixing for a final time; and (g) packaging. Pasteurization and theperformance of quality control checks typically will be carried out atsuitable stages of the process. With respect to step (b), othersolid/liquid separation techniques, such as membrane filtration,decanting or the use of rotary filters or finishers, and the like may beused in place of centrifugation.

[0027] The general overall process may be run at various temperatures.However, it is preferred that the overall process be performed atrefrigerated temperatures (i.e., less than about 45° F. and preferablybetween about 35° F. and 45° F.) to produce a higher quality juiceproduct. It has been determined that the quality of the resulting juiceproduct is greatly enhanced by conducting the process at these lowtemperature levels, even though this would be expected to reduce theefficiency of the solid/liquid separation of step (b) and the ionexchange efficiency of the resin of step (c). It has been found thatvery satisfactory results and minimal negative operational aspects havebeen experienced.

[0028] A schematic diagram illustrating steps (b) through (f) of theprocess of producing a low-acid single strength juice product is shownin FIG. 1, as well as the system by which it is carried out. In thisillustration, single strength orange juice (usually pasteurized) entersthe system at 10 and flows into a centrifuge feed tank 12.Simultaneously, a portion of the single strength juice also is directedinto a blend tank 14 for later combination with the deacidified juice.Optionally, a portion of the untreated juice may be diverted to a bypassline 15 so that it can be added back to the treated juice immediatelyafter deacidification, the importance of which is discussed below.

[0029] From-the centrifuge feed tank 12 the juice flows into one or morecentrifuges 16 for separation of the solids from the juice. Theseparated solids (and a small quantity of juice) are diverted directlyto the blend tank 14, or as illustrated into a recombine tank 17, whilethe remainder is tested to determine whether sufficient separation hasbeen accomplished.

[0030] This testing provides a volume percent value, based upon thetotal volume of the juice, measured by the method described by D.Kimball in “Citrus Processing Quality Control and Technology,” 1991,incorporated by reference hereinto. This measurement procedure issummarized generally as follows for orange juice. 11.8° brix juice at26° C. is poured into a 50 ml centrifuge tube, which is inserted into acentrifuge. For a centrifuge with a spacing of 11.5 inches, thecentrifuge is run at 1500 rpm for 10 minutes. The pulp level is read,and the value is divided by 50 ml to determine the volume percent.

[0031] In the illustrated embodiment, the thus determinied suspendedsolids in the centrifuged juice is selected to be not greater than 1volume percent. Acceptable results can also be obtained for suspendedsolids of up to about 3 volume percent if the average particle sizedistribution is 10 microns or less. Usually, the suspended solids willbe less than about 2 volume percent of the total volume of thecentrifuged juice. The quantity of suspended solids is limited by theability of the reduced-solids juice to easily pass through the resincolumn. If the desired suspended solids volume is not attained, thesolids-reduced juice is returned to the feed tank 12 for furthercentrifugation or other separation, or same can be transferred to theblend tank 14 as desired.

[0032] If the suspended solids are at or below the selected maximumvolume percent, the juice then is treated or otherwise processed toinactivate or remove enzyme, for example by heat treatment. This alsocan be used to pasteurize, if needed. If the juice has been previouslythus treated or pasteurized, it goes directly from the centrifuge 16 tothe ion exchange resin columns 18, 20 for deacidification in accordancewith the present invention. If not, the juice is directed from thecentrifuge 16 to a balance tank 22. It is then rapidly heated at 24, andthen chilled, before being directed to the resin columns 18, 20.

[0033] As illustrated, the process and system utilize a pair ofidentical ion-exchange resin columns 18, 20. This permits continuousoperation of the system, as one column of the pair can be recharged(typically with a basic medium such as but not limited to sodiumhydroxide—NaOH, or potassium hydroxide—KOH, or a combination of basessuch as these), while the other resin column in the pair is being usedto deacidify the juice.

[0034] With reference to FIG. 2, each resin column 18, 20 is partiallyfilled (approximately half-filling being shown) with ion exchange resinbeads 26. The composition of such beads is well-known. See, for example,U.S. Pat. Nos. 4,522,836 and 4,666,721 which are incorporated hereintoby reference. Through a series of piping and flow control valves wellknown in the art, the resin columns 18, 20 are configured to selectivelyadmit either juice or water.

[0035] In this illustrated embodiment, such inflow can be through one oftwo inlet ports. Inlet port 28 is configured so that the fluid flowingtherethrough enters at the top of the resin column, approximately halfthe column height above the top of the bed of resin beads 26. Inlet port30 is a “downcomer”, i.e., it is configured so that fluid flowingthrough it enters the resin column only a short distance above the bedof resin beads 26.

[0036] The illustrated downcomer has a member between its outlet(s) andthe resin bed surface so that the outflow cascades and enters the resinbed in a diffused manner so as to minimize the disturbance of the resinbeads by fluid flowing out of inlet 30. To this end, the opening in theinlet 30 is illustrated to be spaced above a deflector plate 31. Thespacing should be adequate to allow for a 25 percent to 30 percentexpansion of the resin beads during the course of the process. Aftersuch expansion, the bed surface remains spaced from the port 30 or plate31, preferably by from about 2 to 4 inches.

[0037] The top of each resin column includes an air vent 32, as iscustomary. Also customary is an exit port 34 (and valve) at the bottomof each column, thus permitting fluid contained in the column to bedrained by gravity, or by pressure application, in a known manner.Typically when pressure is applied, it is by air or other gas.

[0038] In keeping with the invention, a deacidification process andsystem are provided that utilize a “juice dome” in the resin column toinsure adherence to SOI requirements for the NFC juice and to minimizeyield loss during processing.

[0039] With reference to FIG. 3, the “juice dome” deacidificationprocess is illustrated. Only a single resin column is illustrated, itbeing understood that the other resin column of the pair is beingrecharged and is, thus, off-line. Any number of resin columns can beprovided to satisfy flow requirements. In its INITIAL condition, theillustrated resin column is freshly recharged and filled with water, sothat the portion of the resin column above the level of the resin beads(i.e., the “dome” of the column) is substantially filled with water.This illustrates the “charged” phase.

[0040] The dome then is transitioned from being filled with water tobeing filled with juice. Thus, as shown in STEP 1A, water is drainedfrom the column to create a head space in the dome. This may beaccomplished by either the force of gravity or by the application of airpressure to the top of the column. During this phase of transition fromthe charged phase to a “sweeten-on” phase, preferably only a portion ofthe water is drained from the column, so that the resin beads remainwetted, whether completely submerged or not. Keeping the resin beadswetted helps to insure that the beads do not dry out, which can resultin the empty spaces in the beads filling with air. Such captured aircannot be easily displaced, thus reducing the surface area of the beadsavailable for deacidification, and reducing the efficiency of theprocess.

[0041] Then, as shown in STEP 1B, the single strength juice flows intothe dome, or head space. The flow continues until a desired volume ofjuice is positioned within the dome, for example until the upper volumeportion is filled. Preferably, this flow introduces the single strengthjuice from the middle-level or downcomer inlet port 30, while air isvented through the top of the column. In this step, when the dome is tobe filled completely with juice, the flow of juice to the column isstopped once the upper volume portion is full. This is the “juice dome”formation stage.

[0042] The next steps constitute a transition to the production stage ofthe deacidification process. This is known as the “sweeten-on” phase ofthe deacidification process and system, and is shown as STEP 2A, STEP2B, and STEP 2C. First, as shown in STEP 2A, water is pushed out of theresin bed by introducing single strength juice into the column,preferably through the top inlet port 28. The water is drained from thecolumn.

[0043] At a selected point, the outflow need no longer be drained aswaste, but it can be collected for recovery of juice components as thejuice content increases. As can be appreciated, the “interface” is amixture of water and juice or diluted juice. When this outflows, it canbe collected for uses other than as single strength or NFC juice. Thisoutflow can be monitored by tracking parameters such as brix and/orcolor. Generally, at least one SOI criteria parameter, and if possiblemultiple parameters, will be tracked. Also, this can be determined bytracking time of flow at a known flow-rate. As shown in illustrativeSTEP 2B, the diluted juice stream is diverted to a secondary streamrecovery tank and can later be used in other products which are notrestricted by the SOI requirements for the single strength juice.

[0044] Then, when it is determined that the deacidified juice exitingthe column meets SOI criteria of the single strength juice, product canbe collected as deacidified single strength or NFC juice. This isgenerally shown in STEP 2C. With the invention, this is accomplishedafter a turn over of as little as one resin Bed Volume. This is thevolume of the beads within the vessel. Somewhat greater than one BedVolume can be displaced before diverting the outflow to production, suchas after about 1½ Bed Volumes, to provide a measure of safely to assurethat only juice meeting SOI criteria is collected as single strength orNFC product.

[0045] Juice continues to be introduced into the column such as throughthe top inlet port 28, and the deacidified juice continues to bedirected to production, as shown in STEP 3. This production phasecontinues until production is stopped according to program. This may beat a point when the acidity of the deacidified juice has increased to acertain pre-determined value, meaning that the resin beads are “spent”and that the resin column needs to be regenerated.

[0046] A further transition phase transforms the resin column from thespent state to the “sweeten-off” phase. The dome of the column istransitioned from containing juice to containing water, as shown in STEP4A and STEP 4B. First, as shown in STEP 4A, the juice in the dome ispushed out of the column by either gravity or air pressure at the top ofthe resin bed, usually with the deacidified juice exiting the columncontinuing to be directed to production. Then, as illustrated in STEP4B, the outlet of the column is closed and the dome of the column isfilled by introducing water, preferably from the middle-level ordowncomer inlet port 30 (unless resin disturbance is not a concern),with air being vented through the top of the column. Water is introducedinto the column until the dome is completely filled, at which time waterflow to the column is stopped.

[0047] Next comes the “sweeten-off” phase of the process and system, asillustrated in STEP 5A, STEP 5B, and STEP 5C. First, as shown in STEP5A, the outlet is opened and more water is introduced into the columnthrough the top outlet port 28 so that the remainder of the deacidifiedjuice is pushed out of the resin bed, usually going to production. Thiscontinues until the juice exiting the column no longer meets SOIcriteria for the juice. In most cases, at least ¼ bed volume of juicewill be recovered as product at this stage. This has been found toprovide a good measure of safety to insure SOI is maintained.

[0048] Then, as shown in STEP 5B, the interface or mixture of water andjuice or diluted juice is pushed out of the column by additional waterentering through inlet port 28, and the diluted juice stream preferablyis diverted to the secondary stream recovery tank described above. Thetiming of this diversion away from production is determined as generallydiscussed herein with respect to the “sweeten-on” phase. Typicallythis-will be at a maximum of one bed volume of outflow.

[0049] Then, when the outflow of the diluted juice stream becomes sodilute that it is no longer economically feasible to collect, thediluted juice stream is diverted, such as to the drain, as shown in STEP5C. The column is then taken off-line for recharging in accordance withgenerally known principles, at the end of which it is returned to thecharged phase, typically being filled with water as in the INITIAL stepof FIG. 3.

[0050] By use of this “juice dome” process and system, the juice yieldhas been increased approximately 10 percent, as compared to a standardmethod using a “water dome.” Specifically, the “juice dome” facilitatescontrol of the water-juice interface in the resin column. As aconsequence, the number of Bed Volumes of liquid that are processed bythe resin columns during the transitions to and from the productionphase of the deacidification process is minimized, thus minimizing thedilution of the NFC or single strength juice that would otherwise bewaste or be suitable only for non-NFC juice products and the like. Aslittle as one Bed Volume of liquid is needed for the sweeten-on phasebefore single strength SOI criteria are reached. Less than 2 Bed Volumesof liquid are processed during sweeten-off phase before the diluteddeacidified juice is no longer suitable to recover for use in non-NFCproducts and the like.

[0051] Further advantages accrue to the use of the deacidificationprocess and system described above. Specifically, the introduction ofthe juice (or water) from the middle-level or downcomer inlet port 30 tofill the dome minimizes the potential for undesirable disturbance of theresin beads. Including the plate 31 further enhances this advantage.Introducing the juice from the top inlet port 28 during the juiceprocessing portion of the procedure, rather than through the downcomerinlet port 30, also minimizes stagnant juice in the dome and keeps thejuice that remains flowing during processing.

[0052] After the juice is deacidified as described above, it is directedto a batch tank or blend tank 14 for final mixing. Preferably, this flowis first into the recombine tank 17 where it is combined with thesolids-rich flow out of the separator 16. This combined flow then entersthe blend tank 14.

[0053] At least in the initial stages of deacidification when the resincolumn is most effective, i.e., the initial “Bed Volumes” of juicepassing through the column, the acidity level of the deacidified juicemay be sufficiently low—and the pH sufficiently high—that undesirablemicrobial activity in the deacidified juice could occur. Thus, asmentioned above and if desired, a portion of non-deacidified juice maybe added back to the deacidified juice immediately upon its flow out ofthe resin columns in order to raise the acidity—and lower the pH—of theresulting blend to a level that discourages microbial activity. A pH ofabout 4.5 or below is effective for this purpose.

[0054] In practice, the immediate addition of untreated juice in a ratioof between about 2:1 and about 1:1 with respect to the deacidified juicemay be necessary for the first 10 to 12 Bed Volumes of deacidified juiceto keep the pH lower than about 4.5. See the plots of pH versus ratio ofuntreated juice to treated juice taken at various Bed Volumes (i.e., 1,3, 6, 9, 12, 15 and 18) shown in FIGS. 4A, 4B and 4C, which empiricallyshow that ratios of untreated juice to treated juice of between about1:1 and about 2:1 should ensure a pH of 4.5 or below. Depending upon theprecision of the pH measurement techniques or pH monitor, in practice itcan be desirable to provide a safety cushion by targeting a lower pH,e.g., 4.4 or 4.3. After the pH of the deacidified juice exiting theresin column drops below 4.3-4.5, the immediate addition of untreatedjuice to raise the acidity is no longer necessary.

EXAMPLE 1

[0055] The following example illustrates the process for making low acidorange juice from NFC orange juice. The following are the parameters forthe example: the titratable acidity of the NFC orange juice enteringinto the system at 10 is 0.68 percent, while the flow rate for the NFCfeed is 133 gallons per minute (gpm). The cycle time for the process is6 hours, resulting in a batch size of approximately 48,000 gallons. Thevolume of the resin in the column is 50 cubic feet, and the timerequired to regenerate the column is 3.5 hours.

[0056] From the inlet 10 to the system, 83 gpm of untreated juice isdirectly diverted to the blend tank 14. The remaining 50 gpm ofuntreated juice is directed to the centrifuge 12. The untreated NFCjuice has the following characteristics: Temperature (35° F.); Acidity(0.68% w/w); pH (3.8); Suspended solids (11%); Oil (0.030% v/v);Ascorbic acid (40.9 mg/100 ml); and Calcium (81 ppm).

[0057] Of the 50 gpm of juice entering the centrifuge, 5 gpm is directedto the blend tank 14. Centrifuging in this example is complete if thepercentage of suspended solids in the centrifuged NFC juice is less than1 percent. After completing centrifugation, the juice has the followingcharacteristics: Temperature (35° F.); Acidity (0.67% w/w); pH (3.8);Suspended solids (1%); Oil (0.022% v/v); Ascorbic acid (39.2 mg/100 ml);and Calcium (77 ppm).

[0058] After centrifuging, 45 gpm of juice goes directly to the resincolumns 18, 20 for deacidification. However, if the centrifuged juicehas not already been pasteurized, it is directed to the balance tank,from which it receives heat treatment. The juice is rapidly heated to apasteurization temperature for a very short duration and thenimmediately chilled so that the product has a final temperature of 40.0°F. The pasteurized juice then is directed to the resin columns 18, 20for deacidification.

[0059] After deacidification, in accordance with the steps describedabove, the deacidified juice stream exiting the resin columns has thefollowing characteristics: Temperature (40° F.); Acidity (0-0.5% w/w);pH (9 to 4.4); Suspended solids (1%); Oil (0.018% v/v); Ascorbic acid(31.1 mg/100 ml); and Calcium (75 ppm). Note that the acidity of thejuice exiting the resin column will vary so as to increase during thecourse of a cycle as the ion-exchange resin loses its effectiveness.

[0060] The deacidified juice is then directed to the blend tank, whereit is mixed with the untreated juice to achieve the final blend havingthe following characteristics: Temperature (36° F.); Acidity (0.58%w/w); pH (4.1 to 4.3); Suspended solids (10%); Oil (0.028% v/v);Ascorbic acid (38 mg/100 ml); and Calcium (56 ppm). At this time,additional oils, minerals and vitamins may be added. In the presentexample, additional calcium is added.

[0061] The blended low acid juice then is directed at a rate of 100 gpmto a pasteurizer, or, if the untreated juice has been pasteurized,directly to a packaging line.

EXAMPLE 2

[0062] In a second example, microfiltration is used to separate thejuice and solids, rather than centrifugation. Otherwise, the basicparameters are identical to those of Example 1. The titratable acidityof the NFC orange juice entering into the system is 0.74 percent; theflow rate for the NFC feed is 133 gallons per minute (gpm); the cycletime for the process is 6 hours; the batch size is 48,000 gallons; theresin bed has a volume of 50 cubic feet; and the time required theregenerate the column is 3.5 hours.

[0063] From the inlet to the system, 83 gpm of untreated juice isdirectly diverted to the blend tank. The remaining 50 gpm of untreatedjuice is subjected to microfiltration. The untreated juice has thesecharacteristics: Temperature (35° F.); Acidity (0.74% w/w); pH (3.76);and Ascorbic acid (45.1 mg/100 ml).

[0064] Of the 50 gpm of juice being subjected to microfiltration, 10 gpmdoes not pass through the filter membrane and constitutes the“retentate”. The retentate is directed to the blend tank. It has thesecharacteristics: Temperature (65° F.); Acidity (0.80% w/w); pH (3.80);and Ascorbic acid (39.2 mg/100 ml).

[0065] The remaining 40 gpm that has passed through the filter membrane,i.e., the “permeate”, has these characteristics: Temperature (40° F.);Acidity (0.71% w/w); pH (3.74); and Ascorbic acid (43.4 mg/100 ml).

[0066] The filtered juice goes to the resin columns at a rate of 40 gpmfor deacidification in accordance with the process described above. Thedeacidified juice has these characteristics: Temperature (45° F.);Acidity (0.38% w/w); pH (4.22); and Ascorbic acid (38.0 mg/100 ml).

[0067] The deacidified juice is then directed to the blend tank, whereit is mixed with the untreated juice and retentate to achieve the finalblend having these characteristics: Temperature (35° F.); Acidity (0.61%w/w).; pH (3.86); and Ascorbic acid (42.5 mg 100 ml).

[0068] Deacidified juices produced by the methods illustrated inExamples 1 and 2 were similar in flavor, and both methods yielded juicesthat were lower in sourness than regular orange juice which has not beendeacidified.

[0069] Thus, a method for deacidifying single strength or NFC juice hasbeen provided that meets objects of the present invention. While theinvention has been described in terms of a preferred process with aspecific example, there is no intent to limit the invention to the same.Instead, it is intended to be defined by the scope of the followingclaims.

1. A process for deacidifying single strength juice including not fromconcentrate (NFC) juice using an ion-exchange column having a lowervolume portion filled with acid-adsorbing resin beads and having anupper volume portion within which the resin beads are not present, thelower volume portion having an exit port, a first inlet port openinginto the upper volume portion at an upper location spaced a givendistance above the resin beads, a second inlet port opening into theupper volume portion at a lower location which is spaced a distanceabove the resin beads which is less than said given distance, theprocess comprising: introducing water into the resin column; draining afraction of the water from the column through the exit port to create ahead space in the column above the resin beads; introducing untreatedsingle strength juice which meets SOI criteria for the single strengthjuice into the resin column through the second inlet port and into thehead space; introducing untreated single strength juice which meets SOIcriteria for the single strength juice into the resin column through thefirst inlet port; draining water through the exit port to provide anoutflowing treated liquid and continuing the draining until theoutflowing treated liquid meets or exceeds the SOI criteria for thesingle strength juice; continuing to introduce untreated single strengthjuice through the first inlet port and directing the outflowing treatedliquid to production of deacidified single strength juice; removingtreated juice from the resin column so as to create a head space in thecolumn; introducing water through the second inlet port and into thehead space in the column; and introducing water through the first inletport passing liquid through the exit port to provide an outflowingliquid, and continuing the passing until the outflowing liquid no longermeets the SOI criteria for the single strength juice, at which timetreated liquid is no longer directed to production.
 2. The process ofclaim 1 wherein the untreated single strength juice is introduced intothe resin column through the second inlet port until the head space isfilled with untreated single strength juice.
 3. The process of claim 1wherein the untreated single strength juice is introduced into the resincolumn through the first inlet port simultaneously with the draining ofthe water through the exit port.
 4. The process of claim 1 wherein thesingle strength juice is NFC citrus juice and the outflowing liquid isfirst directed to production of deacidified NFC citrus juice when thebrix of the liquid flowing through the exit port exceeds a minimum brixvalue component of the SOI criteria for the single strength NFC juice.5. The process of claim 1 wherein the water is introduced into the resincolumn through the second inlet port until the head space in the columnis filled.
 6. The process of claim 1 wherein the water is introducedthrough the first inlet port simultaneously with the passing of liquidthrough the exit port.
 7. The process of claim 1 further comprisingrecovering the treated liquid of the draining procedure for furtherprocessing into juice products which need not meet SOI criteria for thesingle strength juice.
 8. The process of claim 1 further comprisingrecovering the treated liquid from the passing procedure for furtherprocessing into juice products which need not meet SOI criteria for thesingle strength juice.
 9. The process of claim 1 wherein the continuingprocedure ceases when the outflowing treated liquid has a pH whichexceeds a predetermined value.
 10. The process of claim 9 wherein thepredetermined value is 4.5.
 11. The process of claim 9 wherein the pHpredetermined value is 4.3.
 12. A process for deacidifying singlestrength juice including not from concentrate (NFC) juice using anion-exchange column having a lower volume portion filled withacid-adsorbing resin beads and having an upper volume portion withinwhich the resin beads are not present, the lower volume portion havingan exit port, the process comprising: introducing water into the resincolumn; draining a fraction of the water from the column through theexit port to create a head space in the column above the resin beads;introducing into the head space untreated single strength juice whichmeets SOI criteria for the single strength juice; draining water throughthe exit port to provide an outflowing treated liquid and continuing thedraining until the outflowing treated liquid meets or exceeds the SOIcriteria for the single strength juice; continuing to introduceuntreated single strength juice and directing treated liquid toproduction of deacidified single strength juice; removing treated singlestrength juice from the resin column so as to create a head space in thecolumn; and introducing water into the head space in the column, passingliquid through the exit port to provide an outflowing liquid, andcontinuing the passing until the outflowing liquid no longer meets theSOI criteria for the single strength juice, at which time treated liquidis no longer directed to production.
 13. The process of claim 12 whereinthe untreated single strength juice is introduced into the resin columnuntil the head space is filled with untreated single strength juice. 14.The process of claim 12 wherein the untreated single strength juice isintroduced into the resin column simultaneously with the draining of thewater through the exit port.
 15. The process of claim 12 wherein thesingle strength juice is NFC orange juice and the outflowing liquid isfirst directed to production of deacidified NFC orange juice when thebrix of the liquid flowing through the exit port exceeds a minimum brixvalue criteria of the SOI for NFC orange juice.
 16. The process of claim12 wherein the water is introduced into the resin column until the headspace in the column is filled.
 17. The process of claim 12 wherein thewater is introduced into the column simultaneously with the passing ofliquid through the exit port.
 18. The process of claim 12 furthercomprising recovering the treated liquids of the draining procedure forfurther processing into juice products which need not meet SOI criteriaof single strength juice.
 19. The process of claim 12 further comprisingrecovering the treated liquid from the passing procedure for furtherprocessing into juice products which need not meet SOI criteria ofsingle strength juice.
 20. The process of claim 12 wherein thecontinuing procedure ceases when the outflowing treated liquid has anacidity which exceeds a predetermined acidity value.
 21. The process ofclaim 20 wherein the predetermined acidity value is a titratable acidityof about 0.6 weight percent.
 22. A process for making a low-acid singlestrength juice including not from concentrate (NFC) juice product,comprising: providing an initial single strength juice flow havingsuspended solids and a known brix; diverting from the initial singlestrength juice flow a first portion of the single strength juice from asecond portion of the single strength juice; separating out thesuspended solids from the first portion of the single strength juice toprovide a solids-reduced single strength juice having not greater thanabout 3 volume percent suspended solids based upon the total volume ofthe solids-reduced single strength juice; providing an ion-exchangecolumn having a lower volume portion filled with ion-adsorbing resinbeads and having an upper volume portion within which the resin beadsare not present, the lower volume portion having an exit port, a firstinlet port opening into the upper volume portion at an upper locationspaced a given distance above the resin beads, and a second inlet portopening into the upper volume portion at a lower location which isspaced a distance above the resin beads which is less than said givendistance; introducing water into the resin column; draining a fractionof the water from the column through the exit port to create a headspace in the column above the resin beads; introducing thesolids-reduced single strength juice into the resin column through thesecond inlet port and into the head space; introducing thesolids-reduced single strength juice into the resin column through thefirst inlet port; draining water through the exit port until the brix ofthe outflowing treated liquid exceeds a pre-determined minimum valuerelative to the brix of the initial citrus juice flow; continuing tointroduce solids-reduced single strength juice through the first inletport and directing treated liquid to production of deacidified singlestrength juice; removing treated single strength NFC juice from theresin column so as to create a head space in the column; introducingwater through the second inlet port and into the head space in thecolumn; introducing water through the first inlet port and passingliquid through the exit port until the brix of the outflowing liquiddrops below a pre-determined value, at which time treated liquid is nolonger directed to production; and combining the deacidified singlestrength juice from the ion-exchange column with said second portion ofthe single strength juice flow and with the separated suspended solidsto achieve a final blend, which is a low-acid single strength juice. 23.The process of claim 22 further comprising adding a portion of theinitial single strength juice flow to the deacidified single strengthjuice immediately after deacidification to lower the pH of thedeacidified single strength juice to a value that discourages microbialactivity.
 24. The process of claim 22 further comprising cooling theinitial single strength juice flow to a temperature of not greater thanabout 45° F. and maintaining the single strength juice at or below thistemperature throughout the process, except during pasteurization orenzyme deactivation, if same is practiced during the process.
 25. Theprocess of claim 22 wherein the separating procedure reduces thesuspended solids in the solids-reduced single strength juice to lessthan about one volume percent, based on the total volume of thesolids-reduced single strength juice.
 26. The process of claim 22wherein the continuing procedure is maintained until such time as theacidity of the treated liquid exceeds a predetermined value.
 27. Aprocess for making a low-acid single strength juice including not fromconcentrate NFC juice product, comprising: providing an initial singlestrength juice flow having suspended solids and a known standard ofidentity (SOI); diverting from the initial single strength juice flow afirst portion of the juice from a second portion of the juice;separating out the suspended solids from said first portion juice toprovide a solids-reduced single strength juice having not greater thanabout 3 volume percent suspended solids based upon the total volume ofthe solids-reduced single strength juice; providing an ion-exchangecolumn having a lower volume portion filled with ion-adsorbing resinbeads and having an upper volume portion within which the resin beadsare not present, the lower volume portion having an exit port;introducing water into the resin column; draining a fraction of thewater from the column through the exit port to create a head space inthe column above the resin beads; introducing the solids-reduced singlestrength juice into the resin column into the head space; draining waterthrough the exit port until the SOI of the outflowing treated liquidmeets or exceeds the known SOI of the single strength juice; continuingto introduce solids-reduced juice and directing treated liquid toproduction of deacidified single strength juice; removing treated singlestrength juice from the resin column so as to create a head space in thecolumn; introducing water into the head space in the column and passingliquid through the exit port until the outflowing liquid has an SOIwhich does not meet or exceed the known SOI, at which time treatedliquid is no longer directed to production; and combining thedeacidified single strength juice from the ion-exchange column with-saidsecond portion juice flow and with the separated suspended solids toachieve a final blend, which is a low-acid single strength juice. 28.The process of claim 27 further comprising adding a portion of theinitial single strength juice flow to the deacidified single strengthjuice immediately after deacidification to lower the pH of thedeacidified single strength juice to a value that discourages microbialactivity.
 29. The process of claim 27 further comprising cooling theinitial single strength juice flow to a temperature of not greater thanabout 45° F. and maintaining the single strength juice at or below thistemperature throughout the process, except during pasteurization orenzyme deacidification, if same is practiced during the process.
 30. Theprocess of claim 27 wherein the separating procedure reduces thesuspended solids in the solids-reduced single strength juice to lessthan about one volume percent, based on the total volume of thesolids-reduced single strength juice.
 31. A low-acid not fromconcentrate (NFC) juice prepared according to the process of claim 22.32. The low-acid NFC juice according to claim 31, said juice being alow-acid NFC orange juice having a titratable acidity of not greaterthan about 0.6 weight percent.
 33. The low-acid NFC juice according toclaim 31, said juice being a low-acid citrus juice having an aciditylower than that of the initial single strength juice flow.
 34. Alow-acid not from concentrate (NFC) juice prepared according to theprocess of claim
 27. 35. The low-acid NFC juice according to claim 34,said juice being a low-acid NFC orange juice having a titratable acidityof not greater than about 0.6 weight percent.
 36. The low-acid NFC juiceaccording to claim 34, said juice being a low-acid citrus juice havingan acidity lower than that of the initial single strength juice flow.